What are my risks to sign over the deed?

As a signer on a mortgage with a person as my spouse, I divorced him and the judge ordered him to get my name off the mortgage. This was never done. He did nothing for his family as far as a will or any other choices. A little more than a year ago, he passed away. This is when the trouble began. Quite far into the home selling, we couldn't clear the title. The bank made major errors in wording. Instead of JTWS as requested, they miswrote as tenants in common. That's why the title won't clear. The buyer wants to get the past due payments up, providing I sign a quit claim deed. Then he is calling himself a second position to my mortgage. I was going to let it foreclose to begin with. Should I just let this buyer take it from here? If he's catching up payments up near $4,000 it does seem worth the risk. Then on to probate. Do I need to go to the court for that? The deceased ex has a living heir. She is unwilling to sign, even for cash. Evidently, there was once a meth bust when her dad was alive and she didn't want it to come back on her in anyway. Can we order her to sign? This is too hard for me to figure out.